KA24DET stock block reliability at 350-400wtq.

[PoorMans180SX]

Here's my situation: I have 4 KA24DE engines available to me, all of them stock. I'm looking for an engine setup to run for the last half of this year and probably all of next in as many drift events that I can enter, probably around 10 per season, as well as a few autocrosses and road course days in between.

I can either turbocharge the KA, or swap to a 5.3 LS. To keep costs below the LS swap, buying internals for the KA is out of the question. A refresh is all that is cost effective (ARP studs and a Cosworth HG). I'm not easy on engines, the soft limiter is my friend. It would however, be very well tuned on Nismotronics, E85, and running a twin-scroll 57mm turbo. 400ft/lbs of torque is the goal.

Who has a stock block KA that has been reliable under these conditions? Anyone? I think it'd be fun to run the KA until I can perfect my LS swap, but if it's not worth it, then so be it.

Let's stick to technical talk guys, I don't care to turn this into a LS-swap debate.

[KAT-PWR]

You are really asking a lot out of those motors. I've been dealing with KA-t's for around 3-4 years now. My current set up is probably the best "budget" reliable build you can do. New pistons(low comp), stock rods, arp hardware, felpro HG. 400whp/350tq reliably (knock on wood)
Another local friend has had his motor (similar specs) together running 400whp/380tq for years. So long its getting pulled and put in another friends car.

The weak part in the ka motor are the pistons, followed by the rods. Martin at Enthalpy advised me to really not push the rods passed 400wtq. And with a stock, non rebuilt motor you are going to blow it fairly quickly, if you dont spin a bearing first. I don't have faith that e85 and a good headgasket are enough to keep the motor together.

Most friends and people i have seen are able to keep their KA's together for more than a couple events when using a t28 making ~300hp and less torque. After that the motors seem to really drop off steeply.
A local (nismofanatic/Cory) managed 500whp on a stock block KA, not tracked, and it did not last long at all on that power. And prior to that he ran around 400 i believe and he said he was rebuilding motors on a regular basis.

If i were you, i would try and aim for 300-350ish whp and less torque. Stay off the limiter or set it lower and pray the rest of the motor is in good shape. I have seen plenty of t25/t28 KA cars that can "keep up" with much faster cars because of their drivers.
Use a turbo that spools quickly and take advantage of the KA's low end torque.

[xpinoyxmk]

Depending on condition of those motors, arp head studs and even a felpro headgasket would suffice. Cosworth even better but if I remember right, its best to have the head and block shaved for a perfect mating surface with that headgasket. If you don't half-ass anything, not go too aggressive with the tune, then you should be good.

Most people don't post their setups that have years on them because they don't really care for these forums but I've seen a ton of them over the years.

[spooled240]

Best case scenario is it will hold but start burning oil. There's been a couple people/companies that pushed stock ka24's to these power levels with moderate success, but the ringlands end up wearing out rather quickly.

edit: in response to xpinoyxmk, I'm one of those people lol Been boosted since 2008ish on stock internals w/ new rings, bearings and gaskets pushing about 270whp/280tq

[smink]

The longest I have gotten out of a stock block turbo ka is a hard year. The engine had good compression numbers to start (170) with a t25 at 11psi and 550cc injectors and an enthalpy tune. Would have much rather had a better tune but it's what I had at the time. Engine ran good and put some STI's to shame on the interstate. But towards the end of the year power started falling off and I swapped in a built bottom end. Which has been running very well for this past year.

Anywho I would stick with low hp numbers and some new pistons. At least factory spec pistons. Maybe some different ring gaps. Not sure how much expansion/contraction the stock rings go through with boost compared to n/a. But it may be something to look into also.

[KAT-PWR]

Additionally i will say with the current KA im building (fully built) i brought 2 blocks to the machine shop with stock bore, aftermarket pistons, and both blocks when honed would've given me a loose (beyond spec) piston to wall clearance. Sold those pistons and got .20 overs.
Food for thought

[PoorMans180SX]

Thanks guys, the advice helps.

I may just stick with the old KA after all, seeing as they are so plentiful at the moment. I'll most likely refresh an engine and run it at 300whp for the season. If I like it enough I may even build a bottom end and head and make some real jam.

I was talking with nissanfanatic on KA-T and he was saying the rods definitely didn't like the 450wtq he was making, haha.

[KAT-PWR]

Yeah Cory is rad. After sending him a PM a year ago he finally logged in and responded. Turns out he literally lived 1 mile from my house. Very knowledgeable guy, hopefully hell be back in the game soon. If you have any questions feel free to PM me.
With how many people bail on the KA if you deal hunt you can do a built block for quite cheap. I picked up a built (except rods) motor for 350 came with two more motors worth of parts. 225 for eagle rods, machine work. Fully built block for less than 1000

[PoorMans180SX]

Yeah Cory is rad. After sending him a PM a year ago he finally logged in and responded. Turns out he literally lived 1 mile from my house. Very knowledgeable guy, hopefully hell be back in the game soon. If you have any questions feel free to PM me.
With how many people bail on the KA if you deal hunt you can do a built block for quite cheap. I picked up a built (except rods) motor for 350 came with two more motors worth of parts. 225 for eagle rods, machine work. Fully built block for less than 1000

Yeah true, I've seen too many eagle rods break to run them though, maybe some Manley's.

[FeArZ]

Not to get off topic, but are you guys running the stock used oil pump when you rebuild engines? I heard Nissan discontinued the factory production of new ones.

[EDT007]

Wow, maybe I've been lucky (knock on wood). The car has been boosted for over 9 years (80k miles) at about 260rwhp without any issues (currently 146k and still running strong). I think you could benefit alot by going over to ka-t.org and reading up. There's plenty of guys on there running reliable 400rwhp (not sure on tq) setups. Goodluck!

[spooled240]

I rebuilt my oil pump with OEM internals. Haven't had any problems so far.

[Drifting Kalamari]

Eagle rods...(when I had them) I was told they aren't well balanced and machined, Chinese products. After machining and balancing them they are just as good as other rods. I only had them for a little bit so I had no complaints

[PoorMans180SX]

Wow, maybe I've been lucky (knock on wood). The car has been boosted for over 9 years (80k miles) at about 260rwhp without any issues (currently 146k and still running strong). I think you could benefit alot by going over to ka-t.org and reading up. There's plenty of guys on there running reliable 400rwhp (not sure on tq) setups. Goodluck!

I've read pretty much everything on ka-t.org, thanks though. Build engines do 400wtq no problem, but that wasn't my original question.

Eagle rods...(when I had them) I was told they aren't well balanced and machined, Chinese products. After machining and balancing them they are just as good as other rods. I only had them for a little bit so I had no complaints

The old ones seemed to be decent, but as for the last two years, look out.

[EDT007]

I've read pretty much everything on ka-t.org, thanks though. Build engines do 400wtq no problem, but that wasn't my original question.



The old ones seemed to be decent, but as for the last two years, look out.

What I meant to say there are members running reliable 400rwhp setups on stock blocks.